Sheet feeding system for printing presses and the like



Feb. 24, 1959 P. w. LAYDEN 2,874,962

SHEET FEEDING SYSTEM FOR PRINTING PRESSES AND THE LIKE Filed NOV- 16,1953 i 5 Sheets-Sheet l PAUL W. LAYDEN ATTORNEY INVENTOR v Feb. 24, 1959P. wwLAYDEN 62 SHEET FEEDING SYSTEM FOR PRINTING PRESSES AND THE LIKEFiled Nov. 16, 1955 3 Sheets-Sheet 2 I I I I I r I 5 I I i I D INVENTORPAUL w. LAYDEN P. W. LAYDEN Feb. 24, 1959 SHEET FEEDING SYSTEM FORPRINTING PRESSES AND THE LIKE Filed Nov. 16, 19753 3 Sheets-Sheet 3 llllllllllll I ll ll IIIIIIIII I II INVENTOR PAUL w. LAYDEN ATTORNEY SHEETFEEDlNG SYSTEM FOR PRINTING PRESSES AND THE LIKE Paul W. Layden, Salem,Ohio Application November 16, 1953, Serial No. 392,110

6 Claims. (Cl. 271-27) The present invention relates to sheet feedingsystems for printing presses and the like, and more particularly tonovel and improved apparatus for feeding a plurality of paper sheets inrapid succession from a pile thereof into a printing press in accuratelyaligned relation to the latter.

As an overall object, the presentinvention seeks to provide a new andimproved arrangement for separating a plurality of paper sheets from acompact pile or stack thereof, feeding the sheets one at a time, inrapid order and in overlapped relation toward a printing press, andaccurately aligning the sheets with the press immediately prior tofeeding the sheets thereinto.

More specifically, the present invention seeks an improved arrangementfor initially separating'a plurality of paper sheets from a pile thereofso that the sheets may be accurately and positively gripped by a feedingdevice and fed inrapid succession toward a printing press, for example.In this respect the invention contemplates the use of a sheet feedingdevice of the general type shown and described in my co-pendingapplication Ser. No. 220,375 filed April 11, 1951, which has maturedinto U. S. Patent No. 2,714,006, which is positioned over the rear edgeof a pile of sheets and arranged to engage individual sheets and feedthe same in extremely rapid succession, in overlapped or streamfeedrelation, toward a printing device.

As will be readily understood, a plurality of sheets in stacked relationhave a certain tendency to stick together, hampering the properoperation of the feeding device, and in many instances tending'to causefeeding of two or more sheets at a time. This is of course particularlytrue where the sheets have undergone a previous printing operation.Accordingly, the' present invention seeks to provide an improvedapparatus, positioned adjacent the sheet feeding device, for separatingthe sheets prior to engagement of the same by the feeding device, andfor facilitating such engagement whereby the feeding operation may becarried out as rapidly as the capacity of the feeding devicewill permit.

Another object of the invention is the provision of an improved meansfor incorporation into a sheet feeding system of the general typecontemplated, whereby individual sheets of paper fed in overlapped orstreamfeed relation toward a printing press or similar device may beaccurately aligned or registered with suchpress or device prior to beingfed into the same. i a

In many types of printing operations, and particularly in multi-colorprinting, wherein sheets arefed into a press a number of times, adifferent color being applied in each instance, it is necessary that thesheets be in substantially exact registry with the press, lest there benoticeable overlaps and voids in the color scheme, re-

2,874,962- Patented Feb. 24,1959

are fed at a substantially higher rate of speed than in conventionalsystems. i

In connection with the above, it is another object of the presentinvention to provide a sheet registering arrangement for incorporationinto my general feeding system which is operative to quickly andaccurately move misaligned sheets into exact or substantially exactregistry with the printing apparatus and maintainthe sheets in suchregistry until the sheets are gripped and drawn away.

by the press.

Yet another object of the invention resides in the provision of animproved and novel sheet registering device of the type described abovewhich is adapted to exert a high initial guiding force to a misalignedsheet, causing the same'to be moved toward a fixedqguiding member, andto thereafter maintain a substantially reduced guiding force upon thesheet so that the registry thereof is properly maintained until thesheet is gripped and drawn into the press. The desired arrangement issuch that the sheets are rapidly moved into proper registry, so that thefeeding system may be operated at high speed, while upon the sheetsbeing moved into proper registry a reduced guiding force is appliedthereto to prevent buckling or bounce-back of the sheet.

The above and other objects and advantages of the invention will becomeapparent upon full consideration of the following detailed specificationand accompanying drawing wherein is shown apreferred embodiment of myinvention. t

In the drawing:

Figure l is a simplified side elevation of the sheet feeding system ofmy invention; a

Figure 2 is an end elevation of the apparatus of Figure 1;

Figure 3 is an enlarged fragmentary view of .the apparatus of Figure 1,illustrating my improved sheet separating apparatus;

Figure 4 is a fragmentary top plan view of the apparatus of Figure 1illustrating certain details of my improved sheet registering apparatus;

Figure 5 is a simplified fragmentary view of the apparatus of Figure 1,illustrating parts of my sheet registering apparatus; and

sulting in an inferior and in many instances completely and described inmy co-pending application Ser. No.

220,375 filed April 11, 1951, now U. S. Patent No. 2,714,006, wherein aplurality of sheet-engaging suckers 17 rotate generally about an axis18, subject, however, to a modifying motion which is eifected by'a cam19 in such manner that a plurality of suckers 17 are simultaneously insheet-engaging and sheet-moving relation while other suckers 17' areaccelerated and rapidly returned into feeding relation with the pile-10.In accordance with the teachings of my prior invention the suckers 17are preferably of the telescoping type whereby upon the same moving intooperative relation with the pile sheet-engaging cups 18 are moveddownwardly into en,- gagement with the uppermost sheet of the pile 10and then drawn upwardly with the sheet. After a sheet has been movedforwardly a.'short distance the next succeed:

ing sucker engages a sheet and begins to move the same forwardlyunderneath the previous sheet. A continuous stream of such sheets isthus fed in overlapped or streamfeed relation into the conveyor 13 wherethe sheets are brought into registry with the printing press 15 andthen: engaged and drawn into the press 15 by means of a gripping roll 16or other suitable device.

Depending primarily-upon the width of the sheetsto be fed, the feedingsystem of my invention maybe arranged to incorporate one or a pluralityof feeding devices 12. Thus, inthe"illustratedembodiment of theinvention I have-provided a pair of spaced feeding devices positionedadjacent each side of the pile 10, over the rear edge thereof, so thateachsheet is engaged at its rear corners for feeding. Of course, bothfeeding devices 12 are substantially identical and are arranged tooperate. in synchronism. Preferably, a common shaft defining a com monaxis 18 drivesboth devices.

In order to obtain extremely high speed feeding, as has been madepossible by my feeding device 12, it has been found necessary toinsure-proper separation of the sheets of? the. pile 10 to therebyinsure that the same are fed in one-at-a-time relation. And it has alsobeen found desirable to buckle or fluff the uppermost sheet of the pile10 so that the suckers 17 more quickly and readily engage: the sheet forfeeding in the manner desired.

Thus, in accordance with suggestions of the prior art I have positionedadjacent each rear corner of the pile 10 a nozzle 20 of right angularshape, each of the nozzles being provided with apair of elongatedvertically disposed outlet openings 21 directed toward the edge of thepile- 10 adjacent the uppermost few sheets thereof. Each of: the nozzles20 has a. supply conduit 22 communicating with a source of compressedair, not shown, whereby streams of air may be directed toward; the topsheets of the pile; toeifect a separation of the rear edge. portions ofthe sheets.

Positioned directly above the pile 10, adjacent each rear cornerthereof, and disposed generally at right angles with respect to. the.axis; of feeding movement, are suction wheels 23 which are keyed orotherwise connected with shafts 24 and adapted to be rotated therewithat a relatively high rate of speed by any suitable means, not shown. Asillustrated in Figure 3, each of the suction wheels 23 is provided witha plurality of spaced radially directed bores 25,'whichbores areintercepted by a like plurality of axially directed bores 26 locatedconcentrically about the shaft 24. As shown in Figure 1 the outeropenings of the bores are axially elongated so that a substantialeffective suction area is afforded while the circumferential dimensionof the bores is maintained at a minimum. Positioned adjacent each wheel23 in a valving member 27 having, a recess 28 therein which is arrangedtocommunicate with one of the axial bores 26. In the preferredconstruction the valve member 27 is fixed, and the recess 28 is locatedbelow the. shaft 24 so that only the lowermost bore 26 will be in'communication with the recess atany one time. I Also communicating withthe recess 28, and extending outwardly of the valving member 27, is ashort nipple 29 which is adapted to be connected to a suitable vacuumpump or device, not shown, whereby suction may be applied to thelowermost of the radial bores 25 when desired.

Referring again to Figure 2, there is shown a pair of air blast feet 30positioned over the pile 10, adjacent the real-edge thereof and betweenthe spaced feeding devices 12. In" accordance with known feeder designthe feet 30 are provided with forwardly directed nozzle portions 31, andare arranged to communicate with a suitable source of compressed air,not shown, so that when a sheet of p'aper is lifted from the pile 10 bythe feeding devices 12, as'shown in Figure 2, one or more streams orblasts of air may bedirected along the lower surface of the lifted sheetso that the same-is separated and freed from the I underlying sheet foreasy forwardfeeding. Alsoih accordancezwith'known feeder'design, theblast feets30 are;

mounted for timed vertical movement toward and away from the top of thepile-10, the arrangement beingsuch that whenever a sheet is engaged bythe feeding devices 12 the feet 30 rise to permit the engaged sheet tobe withdrawn, whereupon the feet are lowered, simultaneously clampingthe next sheet to the top of the pile and sending a blast of air beneaththe raised sheet to facilitate the feeding thereof toward the press.

If desired, the feet 30- may be further employed as detecting devicesfor the purpose of energizing a pile raising mechanism, not shown,whereby to maintain the top level of the pile- 10 inpredetermined'relation with the feeding devices12. This is also inaccordance with known principles of sheet feeder construction.

The operation of my sheet separatingand feeding arrangement may beascertained by reference to Figures 1-3 of the drawing. As shown inFigure 3, the uppermost few sheets of the pile 10 are initiallyseparated along the rear edges by means of strong air blastsissuing'fromthe vertically disposed openings 21- of the separating nozzles 20. Theuppermost one of the sheets thus separated is forced upwardlyintounderlying relation with the suction wheels 23 which, in accordancewith the teachings of the invention, are rapidly rotating in the.directions indicated so that the lower surfaces of the wheels moveinwardly over the pile. By means of the recess 28 and nipple 29, in thevalving member 27 of each suction wheel, suction is applied to thelowermost radial bore 25 whereby the uppermost sheet of the pile isfrictionally engaged at its rear corners by the wheels 23 and urged inthe direction of travel of the wheels.

. At this time the blast feet 30 are in lowered or clamp ing relation tothe pile 10 so that the uppermost sheet is firmly held in. place. Theresult is that the corners of the upper sheet are buckled upwardly inthe manner shown in Figure 2. And in accordance with the teach ings ofthe.- invention the buckle thus produced is positioned substantiallydirectly beneath the continuously rotating feeding devices 12 so thatthe sheet is'readily engaged by apair of extended suckers 17 of thedevices 12. Substantially at the instant the sheet is engagedv by a pairof suckers 17 the blast feet 30 move upwardly to release the upper sheetand permit forward movement thereof in the manner desired. And aninstant later, after the upper sheet has been moved forwardly asufiicient distance to clear the blast feet 30, the latter are. loweredinto clamping relation with the pile 10 and blasts of air are directedforwardly from the feet 30 to lift the forward edge of the moving'slieetto assist its proper feeding toward the press.

Thev above'described cycle of'operations is repeated in rapid successionin normal operation, causing a continouus streamof sheets to. be fed inoverlapping relation toward the printing pressv 15 in the mannerdesired.

An important feature ofrthe invention is the suction wheel arrangementwherein the. suction openings in the wheels are axially elongatedwhilebeing of a minimum size in a circumferential direction. The arrangementis such that a beating action is imparted to the paperto insure theseparation of the uppermost sheet from other sheets which may tend toadhere thereto. The beating action is, however, effected withoutmutilation of the sheet, as sometimes occurred with apparatus of theprior art. i v

To convey the separated and initially moved sheets from the pile: 10 tothe press 15 it is. conventional to provide a conveyor device 13,comprising a pair of spaced rolls-32 and 33 and a plurality of endlessbelts 34. pressure roll 35 cooperates with the forward conveyor ro1l 32to frictionall'yengagcsheets fed from the pile 10 and causethe same, t'o'be properly conveyed to the moving belts 34'. -An-d-,also in.accordance with usual constructiona suitable hold-down device 36 isprovided which is positionedover the bclts'.34 and arranged to In.accordance with usual construction a suitable bear lightly upon sheetscarried by the belts 34 so a relatively positive feeding movement isafforded. Preferably the hold-down device 36 comprises a plurality ofuniversally movable balls 37 so that sheets may be readily moved in alongitudinal or feeding direction, or in a transverse direction as maybe desired. i

It is of course necessary in most printing operations to accuratelyalign and register the conveyed sheets with the printing press prior tothe sheets being fed thereinto, and this of course contemplatestransverse as Well as longitudinal registry with the printing apparatus.Longitudinal registrymay be readily effected by providing a plurality ofretractible head stops 38 which are arranged to engage the forward edgesof individual sheets as the same are conveyed into position for feedinginto the press 15. As illustrated in Figure l, the press may be providedwith a suitable sheet gripping roll 16 having clamps 39 thereon whichare arranged to engage a longitudinally registered sheet at its forwardedge portion, and at a predetermined time, after retraction of the headstops 38, to draw such sheet into the press 15.

In order to effect proper transverse registry of the conveyed sheets Iconventionally provide a laterally adjustable side guide member 40 (seeFigure 4) which is positioned along one side of the conveyor 13 andwhich is so positioned with respect to the press 15 that any sheet whichis in contact along its side edge'with the guide 40 is in propertransverse registry with the press.

In orderto insure that each sheet conveyed to the press 15 is in properguiding contact with the guide member 40 I have provided a novelarrangement which includes a pair of suction wheels 41 and 42,positioned one on each side of the passline of the conveyor 13 so as tocontact respectively the upper and lower surfaces of each sheet conveyedto the press. In accordance with the teachings of the invention a motor43 or other means is provided to rapidly rotate the wheels 41 and 42 insuch a direction as will tend, when suction is applied to the wheels, tomove the sheet engaged thereby laterally toward the side guide member40.

As previously mentioned, my overall feeding system is intended tooperate at exceptionally high speeds, in the order of 20,000 sheets perhour, for example, and accord ingly the transverse or side registerdevice 14 must also be capable of high speed operation. This isparticularly true since, in the preferred operation of the apparatustransverse movement of the sheets to effect side registry is effectedafter the leading edge of the sheet has engaged the head stops 38 butbefore the gripping roll 16 draws the sheet into the press 15. It willbe readily apparent the interval of time thus afforded for effectingside registry of each individual sheet is of a small magnitude.

Thus, in accordance with the teachings of the invention I have connectedeach of the suction wheels 41 and 42 of the side register device throughvalve members 44 and 45, respectively, and suitable conduit means to asuitable vacuum pump, not shown, so that upon periodic application ofsuction to the continuously rotating wheels 41 and 42 a sheet of paperpositioned therebetween will be caused to move transversely toward andinto contact with the guide member 40. As will be readily understood, inview of the unusually short interval of time provided. for effectingproper side registry of the sheets the suction applied to the rotatingwheels41 and 42 must be of a comparatively high magnitude, so thatwithin the interval provided a sheet may be moved into registry from apossible extreme out-of-register position. Of course, the majority ofsheets fed by the conveyor device 13 will not be so far out of register,and it has therefore been found necessary to reduce the moving force ofthe wheels 41 and 42 toward the end of the registering operation so-thatthe sheets do not become buckled and skewed with respect to the sideguide 40 and press 15. Accordingly, as one of the important features ofmy invention, I have provided a variable relief valve 46 in the to thewheels 41 and 42. As shown in Figure 6, the

valve 46 comprises a body 47 having inlet and outlet parts therein forthe suction line, indicated schematically at 48, and an additional port49 leading to the atmosphere and normally closed off by means of a ballcheck 50 and spring 51. A nut 52 is retained in the upper portion of thevalve body 47, which nut slidably retains a control plunger 53 whichbears against the spring 51.

As the valve 46 is employed in the present apparatus, it is intended tolimit the application of suction to the wheels 41 and 42 by admittingair through port 49 whenever the pressure differential between theconduit 48 and the atmosphere become great enough to lift the ball 50off of its seat. The pressure differential at which the ball 50 islifted may be regulated in the first instance by the setting of nut 50,which provides a. normal limit position for the plunger 53, and in thesecond instance by the setting of the plunger 53 with respect to the nut52. Thus, in Figure 6 the plunger 53 is illustrated in its uppermostposition wherein the ball 50 may be most easily lifted off its seat toadmit air through port 49. If the plunger is depressed, however, thespring 51 applies a greater restraining force to the ball 50 and agreater pressure differential must exist between the conduit 48 and theatmosphere before the ball 50 will lift off its seat. Thus, when theplunger is depressed a maximum suction is applied to the wheels 41 and42, while when the plunger is in its uppermost position the suctionapplied at the wheels 41 and 42 will be at a predeterminedminimum.

To operate the valve 46 synchronously with the feeding of sheets to thepress 15.I have provided a cam 54 which is operatively associated withthe press 15, as schematically indicated at 65, for example. And thearrangement is such that the cam 54 will make one complete revolutionfor each sheet of paper gripped and drawn into the press 15 by the sheetgripping roll 16.

As above mentioned, it is desirable, after a sheet has engagedthe headstops 38, to apply a strong suction force to the wheels 41 and 42 toeffect a rapid transverse movement of such sheet. Accordingly, the cam54 is provided with a raised surface portion 54a which is arranged, uponappropriate rotation of the cam 54, to fully depress the plunger 53 toretain the check ball 50 most firmly in its seat. In accordance with theteachings of the invention, the contoured surface of the cam 54gradually recedes from the raised portion 54a so that, as the camrotates, a progressively diminishing suction is applied to the wheels41. After, for example, about degrees of rotation of the cam 54 the.suction is at a predetermined minimum of, for example, ten percent ofthe maximum, sufiicient to retain the sheets in proper engagement withthe side guide 40 without causing any buckling or skewing of the sheets.

Also in accordance with the teachings of the invention, it is desirableto completely deenergize the wheels 41 and 42 during feeding of sheetsinto the press 15 and during longitudinal travel of the sheets intoengagement with the head stops 38 and for this purpose I have provided asecond valve 55. The valve 55, illustrated In Figure 6, is provided witha spring biased operating plunger 56 which is actuated by a cam 57arranged to rotate in synchronism with the suction control cam 54. Thedesired arrangement is such that upon engagement of a sheet with thehead stops 38 the plunger 56 will be raised to open the suction line 48,whereupon sliction is applied to the wheels 41 and 42 in a controlledmanner, as determined by the contour of cam 54. At

or slightly before the instant a sheet is gripped and drawn into thepress 15 the cam 57 causes the plunger 56 to be depressed to disconnectthe wheels 41 and 42 from the vacuum source therefor, and in accordancewith the preferred operation the wheels remain deenergized until thenextsubsequent sheet engages the head strips 38.

Generally, it is desirable in sheet feeding systems of the type hereincontemplated to provide means for detecting the passage through thefeeding system of a double thickness of paper and to stop the printingpress and feeding system to prevent the passage through the press ofsuch double thickness. In the present apparatus I may advantageouslyemploy the suction wheels 41 and 4-2 for this purpose. As illustrated inFigure 1 the transversely disposed wheels 41 and 42 are provided withrounded outer surfaces whereby sheets traveling parallel to the axis ofrotation of the wheels may readily pass therehetween. Preferably thelower suction wheel 42 is mounted for rotation about a fixed axis, asindicated in the simplified View, Figure 5, while the upper wheel 41 ismounted for rotation about a vertically movable axis afforded by apivotally mounted journal member 58. In the illustrated embodiment ofthe invention, the journal member 58. is spring biased in a downwarddirection, and is provided with an elongated operator 58' which engagesat' its outer end a sensitive type limit switch 59 which is of a typeadapted to be actuated upon a small movement of the operator 58'. Thedesired arrangement is such that upon the passage between the wheels 41and 42 ofa single sheet of paper the switch will remain in a closedcondition, but that upon the passage between the wheels of two or moresheets the switch 59 will open, stopping the press and feeding system sothat the situation may be corrected without damage to the apparatus.

Thus, it should be apparent that I have accomplished the objectsinitially set forth. There is provided by my invention a sheet feedingsystem of a substantially improved nature, capable of feeding sheets inrapid one at-a-time relation, at. substantiallyhigher rates than hasbeen heretofore thought practical, in order that full advantage may betaken of the capacities of the sheet feeding device constituting thesubject matter of my previously identified co-pending application.

One aspect of my improved sheet feeding system relates to the initialseparation of the sheets from a compact pile thereof and theconditioning of the uppermost sheet of such pile for ready engagement bythe feeding device of my prior invention. Thus, I have provided a pairof continuously rotating transversely disposed suction wheels,positioned at each rear corner of the pile, and adapted to engage theuppermost sheet of the pile to buckle the same upwardly at a point belowthe feeding device or devices whereby the same may readily andpositively engage such sheet for feeding toward a printing press or thelike. My separating apparatus is novel in that a beating action isobtained to insure proper separation, while the sheets are not marred orharmed in any way. I obtain this result by providing axially elongatedsuction apertures which afford substantial gripping area while having aminimum circumferential dimension. The arrangement is such that theretends to be an instantaneous release of the paper by one suction openingbefore the next succeeding opening comes into gripping contact with the,paper. Thus, a vibrating or beating action is obtained which insuresthat the uppermost sheet will be properly separated from lower sheetstending to adhere thereto.

Another important aspect of myinvention resides in my novel sideregistering apparatus which is capable of moving individual sheets intoaccurate registry with the printing press or other apparatus at the highrates of speed possible in my overall feeding system. I have provided apair of rapidly and continuously rotating suction wheels to which isapplied, for the positioning of each individual sheet,.an.initiallyhigh'but gradually diminishing suction force, which force is entirelyremoved upon the 'sheet being gripped for feeding intov the press. Thearrangement is such that the sheets are given a relatively strongaccelerating force initially so that proper positioningof the sheets inregistry is assured, while such force is reduced to a small fraction ofthe initial force prior to feeding the sheet into the press wherebybuckling or skewingof the sheet, as might otherwise be caused, is whollyavoided. By means of a novel valving arrangement, which is operativelyassociated with the operation of the printing press, I may energize anddeenergize the side register wheels 41 and 42 at the exact momentsdesired, and may accurately control the force applied by such wheelsthrough the period of energization so that optimum operating results areobtained at all times.

It should be understood, however, that the apparatus herein specificallyshown and described is intended to be representative only, and referenceshould therefore be had to the appended claims in determining the truescope of the invention.

Iclaim:

1. In a sheet feeding system of the type having means for feeding sheetsone at a time from a pile thereof in rapid streamfeed relation toward aprinting press, the combination of a conveying device arranged toreceive sheets in streamfeed relation from said means for feeding, aguide member positioned adjacent said conveying device and located inpredetermined relation with respect to said press, means to applysuction to each of said sheets independently of said conveying devicefor urging the same toward said guide member, said last mentioned meansincluding means to apply aninitial relatively high suction, said lastmentioned means further including means to progressively reduce saidsuctionas said sheet moves toward and abuts against said guide memberprior to feeding said sheet so acted upon into the press, said means toapply suction to each of said sheets comprising a rotating suction Wheeladapted to engage the surface of said sheet, means to supply suction tosaid suction Wheel, said means to progressively reduce said suctioncomprising valve means interposed in said means to supply, said valvemeans comprising a suction passageway, an exhaust port communicatingwith said suction passageway, closure means for said exhaust port,yieldable biasing meansassociated with said closure means for normallymaintaining said exhaust port closed, and means for changing the forceexerted by said yieldable biasing means on said closure means as saidsheet moves toward said guide member.

2. Apparatus according to claim 1 further comprising means to block saidmeans to supply suction to said suction wheel prior to feeding of saidsheet into said press, and means to release said means to block saidsupply of suction upon a subsequent sheet moving into operative relationwith respect to said suction wheel. I

3. In a sheet feeding and registering system comprising conveying meansoperative to feed sheets one at a time from a pile thereof to otherapparatus in rapid streamfeed relation, a guide member positionedadjacent said conveying means, means to apply suction to each of saidsheets independently of said conveying means for urging the same towardsaid guide member, said last mentioned means including means to apply aninitial relatively high suction, said last mentioned means furtherincluding means to progressively reduce said suction as said sheet movestoward and abuts against said guide member, means to block said'means toapply suction after a sheet has moved into registry'with said guidemember, means to release said means to block upon a subsequent sheetmoving into sheet registering'position, said means to block comprisingvalve means, means operating said valve means, and said means operatingbeing operated synchronouslywith the apparatus to which said sheets arefed.

4. In a sheet feeding and registering system comprising conveying meansoperative to feed sheets one at a time from a pile thereof to otherapparatus in rapid streamfeed relation, a guide member positionedadjacent saidconveying means, means to apply suction to each of saidsheets independently of said conveying means for urging the same towardsaid guide member, said last mentioned means including means to apply aninitial relatively high suction, said last mentioned means furtherincluding means to progressively reduce said suction as said sheet movestoward and abuts against said guide member, means to block said means toapply suction after a sheet has moved into registry with said guidemember, means to release said means to block upon a subsequent sheetmoving into sheet registering position, and said means to apply arelatively high suction, said means to progressively reduce saidsuction, said means to block and said means to release said means toblock being operated synchronously with the apparatus to which thesheets are fed.

5. In a sheet feeding and registering system comprising conveying meansoperative to feed sheets one at a time from a pile thereof to otherapparatus in rapid streamfeed relation, a guide member positionedadjacent said conveying means, means to apply suction to each of saidsheets independently of said conveying means for urging the same towardsaid guide member, said last mentioned means comprising means to applyan initial value of suction, said last mentioned means furthercomprising means to progressively change said suction as said sheetmoves toward and abuts against said guide member, said last mentionedmeans comprising a valve having a suction passageway and an exhaustport, closure means for said exhaust port, yieldable biasing meansassociated with said closure means for normally maintaining said exhaustport closed, a protruding operator connected with said yieldable biasingmeans, and cam means operative to move said operator in synchronism withthe apparatus to which said sheets are fed.

7 conveying means operative to feed sheets one at a time from a pilethereof into other apparatus in rapid streamfeed relation, a guidemember positioned adjacent said conveying means, means to supply suctionto each of said sheets independently of said conveying means for urgingthe same toward saidguide member, said last mentioned means comprisingmeans to apply an initial value of suction, said last mentioned meansfurther comprising means to progressively change said suction as saidsheet moves toward and abuts against said guide member, said means toapply comprising a rotating wheel mounted for movement toward and awayfrom said conveying means, and switch means associated with said wheeloperative in the simultaneous passage adjacent said wheel of more thanone sheet thickness to stop said sheet feeding and registering system.

References Cited in the file of this patent Netherlands Oct. 16, 1950

